1. Field of the Invention
The present invention relates to a brake system for preventing a friction rollover of a vehicle.
2. Description of the Related Art
Vehicle rollover accidents have recently received much attention as a product safety concern from the news media and in the judicial court system. Each year, vehicle rollover accidents seriously or fatally injure many vehicle occupants. A large number of these rollovers are single vehicle accidents occurring on dry, flat roads. Frequently, these on-road rollovers are induced solely by emergency steering maneuvers. Typically, in an attempt to avoid an impending collision a driver will steer their vehicle into a sharp emergency turn and thereby induce the rollover. This type of vehicle rollover is referred to as a friction rollover.
Friction rollovers are caused by forces of friction between the tires of the vehicle and the road. When the vehicle is turned sharply, the tires produce lateral forces. The lateral tire forces create a lateral acceleration on the center of mass of the vehicle. The lateral acceleration creates an opposing force referred to as a D'Alembert force. The D'Alembert force and the lateral tire forces act in combination to roll the vehicle outward during the turn. During some sharp turns, the combined forces are strong enough to roll the vehicle over.
Some modern vehicles, such as sport utility vehicles, light trucks, and vans, are more susceptible to friction rollovers than other vehicles. In general, these tall and narrow vehicles are top heavy, that is have a high center of gravity. As a result, sport utility vehicles, light trucks, and vans are more likely to rollover during a sharp emergency steering maneuver. Accordingly, it would be desirable to provide a simple and inexpensive vehicle brake system for preventing friction rollovers.